On January 29, 1850, Henry Clay rose in the Old Senate Chamber to begin the most important debate of his career and to forge one last compromise. A Whig from Kentucky, the “Great Compromiser” entered the Senate in 1806, served intermittently over four decades, and became a star of the Senate’s “golden age.” He resigned in 1842 to run for president but returned in 1849 to seek a compromise solution to the nation’s growing sectional strifeto avoid civil war.

Showing the effects of age and tuberculosis, the 72-year-old statesman proposed eight resolutions to settle the dispute over territories acquired from the Mexican War. The key issue, of course, was whether states carved out of those territories would allow or prohibit slavery. As Clay explained, he proposed an “amicable arrangement of all questions in controversy between the free and slave States.” Adding drama to the occasion, Clay produced an unusual prop. He had recently called for the federal government to buy George Washington’s Mount Vernon estate. In gratitude, a supporter presented Clay with a fragment of wood from Washington’s coffin. Was it portentous that this object had been presented to him, Clay asked? Was it a sign that the nation founded by Washington was dying? “No, sir, no,” thundered Clay, holding up the relic. “It was a warning voice, coming from the grave to the Congress ... to beware, to pause, to reflect before they lend themselves to any purposes which shall destroy the Union.”

For six long months, Clay led the contentious debate. Mississippi Senator Henry Foote suggested combining the resolutions into a single bill, which Clay referred to as a “sort of omnibus” into which Foote introduced “all sorts of things and every kind of passenger.” The idea took hold, and Clay endorsed the Senate’s first “omnibus bill.” He proclaimed it to be “neither southern nor northern. It is equal; it is fair; it is a compromise.” On July 22, Clay delivered his last major speech in the Senate, calling for passage of the omnibus bill. If passed, the North would gain California as a free state and an end to the slave trade in Washington, DC, while the South would get a stronger fugitive slave law and the possibility of western slavery through popular sovereignty. This compromise, Clay insisted, represented the “reunion of [the] Union.”

One week later, the Senate rejected Clay’s proposal. “The omnibus is overturned,” cried opponents. The omnibus strategy had failedrather than solidifying support, it unified opposition. Southerners protested any restriction on slavery, and northerners fumed at the idea of returning fugitive slaves. A disheartened Henry Clay headed north to restore his failing health.

The omnibus bill died, but Clay’s Compromise of 1850 survived. The cause was adopted by Stephen Douglas of Illinois, who disassembled the omnibus and repackaged it into five separate bills, winning enactment of each major provision. Clay’s last compromise helped to stave off civil war for another decade. When the Old Kentuckian died in 1852, he went to his grave believing his compromise had saved the Union.